Platelet adhesion involves a novel interaction between vimentin and von Willebrand factor under high shear stress

Abstract

• Vimentin expressed on the platelet surface serves as adhesive receptor for VWF.The interaction between platelet receptor glycoprotein Iba and the A1 domain of von Willebrand factor (VWF) mediates tethering/translocation of platelets to sites of vascular injury. Unexpectedly, we observed platelets translocating over A1A2A3 domains protein slower than on A1 domain at high shear stress. This observation suggests an additional interaction between A domains and an adhesive receptor. We investigated vimentin because we have data showing the interaction of vimentin with the A2 domain of VWF. Moreover, vimentin is expressed on the platelet surface. This novel interaction was analyzed by using purified VWF, recombinant proteins, anti-vimentin antibodies, parallel flow chamber adhesion assays, flow cytometry, and vimentin-deficient murine platelets. The active form of VWF bound to vimentin, and the purified A2 domain blocked that binding. The interaction of a gain-of-function A1A2A3 mutant with platelet was reduced using anti-vimentin antibody. Platelet adhesion to wild-type (WT) A1A2A3 protein, collagen, and fibrin(ogen) was inhibited (32-75%) by anti-vimentin antibody under high shear stress. Compared with WT mice, platelets from vimentin-deficient mice had a reduced flow-dependent adhesion to both collagen and purified murine VWF. Last, the vimentin knockout mice had a prolonged tail bleeding time. The results describe that platelet vimentin engages VWF during platelet adhesion under high shear stress. (Blood. 2014;123(17):2715-2721 Introduction Atherothrombotic events, including acute coronary syndrome and stroke, are the result of platelet adhesion and activation on the ruptured atherosclerotic plaques. This platelet-mediated arterial thrombosis starts with the contact of the rapidly flowing platelets to components of the damaged blood vessel. von Willebrand factor (VWF), a multimeric plasma and subendothelial glycoprotein, is relevant in mediating platelet adhesion and activation at sites of lesions in the coronary arteries, where high shear conditions prevail.1,2 VWF captures the circulating platelets through its interaction with the platelet receptor glycoprotein (GP)Ib/IX/V complex. This interaction is responsible for the tethering, rolling, and activation of platelets that eventually become firmly adhered, leading to thrombus formation within a coronary artery. 3,4 Mature VWF consists of a 2050-residue subunit formed by domains arranged in the order of D9-D3-A1-A2-A3-D4-B-C. 5 The A1 domain contains the binding site for the platelet receptor GPIba 6 ; the cleavage site for the enzyme ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs)-13 is localized in the A2 domain, 7 and the A3 domain binds to collagen. 8 Unlike the A3 domain, both the A1 and A2 domains do not have access to their ligands until their domain structure is altered.9 This structural modification can be induced by mutations, 10 hydrodynamic forces, 11 immobilization on a surface, or artificially with the modulator ristocetin....

Free hemoglobin increases von Willebrand factor–mediated platelet adhesion in vitro: implications for circulatory devices

“…[13][14][15] Thus, A1 binding to Hb, like collagen and botrocetin, may induce a conformational change that increases the surface available for interaction with GPIba, 20 and/or the Hb bound to the A1 domain forms a new and stronger interface for GPIba binding. 22 In fact, the binding of the more active A1(R1450E)A2A3 mutant 18 to GPIba was slightly increased by free Hb (supplemental Figure 4).…”

“…Similar results were observed when blood was perfused over the fragment A1A2A3 domain protein, which functions like VWF but lacks the site for the GPIIb/IIIa receptor. 19 Contrary to the rolling platelets with whole blood (Figure 2C), 18 free Hb induced the formation of both firmly stable microthrombi and rolling microaggregates ( Figure 2D and supplemental Figure 2A, respectively). Free Hb also increased the adhesion of flowing fixed platelets to the VWF-coated surface at high shear stress (supplemental Figure 2B).…”

“…17 We used the gain-of-function A1(R1450E)A2A3 mutant to analyze the effect of free Hb on VWF-GPIba binding. 18 Platelet-rich plasma containing the mutant and purified Hb were mixed with rabbit anti-VWF antibody (10 mg/mL; Dako) followed by a goat anti-rabbit-conjugated Alexa Flour 647 (20 mg/mL). The platelets were fixed with 1% formaldehyde and analyzed using Image Stream.…”

The shear stess profile of the pivotal fenestrated endograft at the level of the renal branches: A computational study for complex aortic aneurysms

“…[18][19][20] Mohabbat et al 21 documented that uncovered stents present stenosis at both proximal and distal stent-segments, whereas this occurs only at the distal end (i.e. the transitional zone) of the covered stents.…”

The Dynamic Duo of Small Heat Proteins and IFs Maintain Cell Homeostasis, Resist Cellular Stress and Enable Evolution in Cells and Tissues

“…(Bar et al 2014 ;Caulin et al 2000 ;Ku et al 2007 ;Alam et al 2013 ;Weerasinghe et al 2014 ); vimentin, e.g. (Eckes et al 1998 ;Da et al 2014 ;Perlson et al 2005 ); GFAP, e.g. (Hagemann et al 2006 ;Li et al 2008 ;Lundkvist et al 2004 ;Nawashiro et al 1998 ); desmin, e.g.…”